"This release adds support for bcache, which allows to use SSD devices to cache data from other block devices; a Btrfs format improvement that makes the tree dedicated to store extent information 30-35% smaller; support for XFS metadata checksums and self-describing metadata, timer free multitasking for applications running alone in a CPU, SysV IPC and rwlock scalability improvements, the TCP Tail loss probe algorithm that reduces tail latency of short transactions, KVM virtualization support in the MIPS architecture, many new drivers and small improvements."